This is actually old news. It’s been known for years that the Martian soil is deeply infused with perchlorates and that they are distributed across most of the planet. The Phoenix lander discovered that the soil is alkaline and full of perchlorate salts.
A perchlorate is a chemical compound, and its dominant industrial use on Earth is in rocket fuel (for rockets, and for fireworks). It’s also used in fertilizers.
They’re likely pretty poisonous to humans and most other life too. They interfere with the thyroid and possibly lung function.
NASA doesn’t think this is a showstopper for human beings stepping foot on to Mars, and maybe living there permanently but Mars has another problem: its surface is also radioactive because it lacks a global magnetic field and ozone layer. Significant amounts of ionizing radiation hits the surface.
A new study suggests this combination of radiation and perchlorates actually sterilizes the surface.
Perchlorates have been identified on the surface of Mars. This has prompted speculation of what their influence would be on habitability. We show that when irradiated with a simulated Martian UV flux, perchlorates become bacteriocidal. At concentrations associated with Martian surface regolith, vegetative cells of Bacillus subtilis in Martian analogue environments lost viability within minutes. Two other components of the Martian surface, iron oxides and hydrogen peroxide, act in synergy with irradiated perchlorates to cause a 10.8-fold increase in cell death when compared to cells exposed to UV radiation after 60 seconds of exposure. These data show that the combined effects of at least three components of the Martian surface, activated by surface photochemistry, render the present-day surface more uninhabitable than previously thought, and demonstrate the low probability of survival of biological contaminants released from robotic and human exploration missions.
That’s from the abstract.
The chances of anything coming from Mars have taken a downward turn with the finding that the surface of the red planet contains a “toxic cocktail” of chemicals that can wipe out living organisms.
Experiments with compounds found in the Martian soil show that they are turned into potent bactericides by the ultraviolet light that bathes the planet, effectively sterilising the upper layers of the dusty landscape.
The discovery has wide-ranging implications for the hunt for alien life on the fourth rock from the sun and suggests that missions will have to dig deep underground to find past or present life if it lurks there. The most hospitable environment may lie two or three metres beneath the surface where the soil and any organisms are shielded from intense radiation. “At those depths, it’s possible Martian life may survive,” said Jennifer Wadsworth, a postgraduate astrobiologist at Edinburgh University.
Wadsworth’s research was driven by the discovery of powerful oxidants known as perchlorates in the Martian soil some years back. Hints of perchlorates first showed up in tests performed by Nasa’s Viking lander missions 40 years ago, but were confirmed recently by the space agency’s Phoenix lander and Mars rover, Curiosity. In 2015, the Mars Reconnaissance Orbiter spotted signs of perchlorates in what appeared to be wet and briny streaks that seeped down Martian gullies and crater walls
So, no Martian potatoes.
NASA also stated yesterday that it simply doesn’t have the money to send people to Mars and even if it did, it’s going to miss the next window for a “fast” trip anyway—that’s next year. The next one after that is in the 2030s. We don’t really have the technology to land either. There’s likely no magic drive coming to make this an easier trip either (I’m not all that hopeful about the VASMIR even if NASA apparently is.)
But ever the optimists, the scientists in the linked Guardian article don’t see this as a total showstopper. After all, one can dig down. But James SA Corey’s The Expanse, where a couple billion people live on a Mars being actively terraformed, is likely not our future.
I don’t think there’s anything wrong with dreaming though, or sending robots, or even people. I just don’t think people will ever be stepping foot on Mars.